This invention relates to earth coupled heat pump systems. More specifically, it relates to interface equipment installed between a water source heat pump and a closed loop buried heat exchanger.
An object of this invention is to provide interface equipment in modular form.
A further object of this invention is to provide interface equipment that can be all plastic in order to cooperate with present practice of using calcium chloride, glycols, or alcohols as antifreeze.
A further object of this invention is to provide equipment that can be used with or without visual instruments.
A further object of this invention is to reduce installation procedures to a minimum.
A further object of this invention is to provide full access to a closed loo buried heat exchanger for filling, purging, filtering, cleaning, antifreezing, and corrosion inhibition.
A further object of this invention is to prevent air from entering the buried heat exchanger loop during service.
A further object of this invention is to provide a system whose heat pump loop can be purged with an installed circulator pump.
A further object of this invention is to provide an appropriate arrangement that will minimize spillage during service.
Another object of this invention is to provide the system with an accumulator tank for extending the time required for the system to leak down.
Another object of this invention is to provide an accumulator tank that cannot enter air into the buried heat exchanger loop as the system leaks down to atmosphere or during setup procedures.
Another object of this invention is to provide the system with auto shutdown because of the loss of static pressure.
Another object of this invention is to provide a means for separating solid particles from the circulating fluid. Solid particles can be construction dirt, generated by corrosion, or the result of precipitation.
Another object of this invention is to provide a means from separating air from the circulating fluid.
BRIEF DESCRIPTION OF THE INVENTION
Briefly, this invention provides modular interface equipment between a heat pump assembly and a buried heat exchanger to provide simplicity of installation and the reliability of manufactured parts. All parts can be pressure tested at manufacture. The modular components allow for matching of pumping power of circulator pump with respect to system pressure drop. The system can be used blind, or with temperature and pressure instruments. A low pressure shutoff switch can protect the circulator pump from cavitating and running dry.
The modular interface equipment includes a first valve assembly connected to one end of a ground buried heat exchanger and a second valve assembly connected to an opposite end of the ground buried heat exchanger. An accumulator tank is connected between the first valve assembly and an end of a conduit of a heat exchanger of the heat pump assembly. A circulator pump is mounted between the second valve assembly and the other end of the conduit. Air can be held in the upper part of the accumulator tank forming a cushion permitting variatio of the pressure in the system. During normal operation of the system, valves in the valve assemblies are set to direct liquid from the circulator pump through the conduit of the heat exchanger of the heat pump assembly, through the accumulator tank, and through the ground buried heat exchanger back to the circulator pump. During servicing, valves of the valve assemblies are set to close off the ground buried heat exchanger, and the valve assemblies are connected together by a cross-over/bleed assembly provided with an air bleeding fitting. The circulator pump directs liquid through the conduit of the heat exchanger of the heat pump assembly, the accumulator tank, and the cross-over fitting back to the circulator pump. Heavy solid particles can settle to the bottom of the accumulator tank where a drain fitting at the bottom of the accumulator tank can be opened to release the heavy particles. Air can be bled from the crossover/bleed assembly through the air bleeding fitting. Additional liquid can be introduced through a valve at a low point in the system by pump action. Excess air can be removed from the accumulator tank through a bleed fitting therein spaced a selected distance from the top thereof.
The above and other objects and features of the invention will be apparent to those skilled in the art to which this invention pertains from the following detailed description and the drawings in which: